1. Field of the Invention
The present invention relates to a sealing structure.
In more detail, the present invention relates to a sealing structure providing a waterproof mechanism of an electronic equipment and a connector.
2. Description of the Conventional Art
In recent days, a high waterproof function is demanded, while a downsizing is advanced, for a waterproof connector which is used in an electronic equipment such as a cellular phone, an automotive wiring harness and the like.
In order to provide the waterproof function to the electronic equipment constructed by a plurality of spaces, it is necessary to make housings constructing the respective spaces to be airtight, and electrically connect the spaces by a flexible board or the like.
In this case, there have been proposed a method by providing terminals on wall surfaces of the housings which form the respective spaces, and connecting the terminals with wiring members, and a method by putting the wiring member through the wall surfaces of the housings and caulking gaps made between the wiring member and the housings with an adhesive agent or the like.
However, the mode that the terminals are provided on the wall surfaces of the housings has a problem that the equipment is enlarged in size. The method by caulking the gap made between the wiring member and the housings with the adhesive agent or the like causes a problem that a dissembling work and a reassembling work are hard.
Accordingly, as shown in FIGS. 7 and 8, there has been proposed a mode that sealing members are integrally formed on the flexible wiring board (Japanese Unexamined Patent Publication Nos. 2003-142836 and 2004-214927).
In the mode shown in FIG. 7, frame body shaped sealing members 301 corresponding to shapes of respective housings (not shown) are integrally formed with a flexible wiring board 100.
The flexible wiring board 100 extends through each of the sealing members 301, and electronic parts are mounted within regions surrounded by the respective sealing members 301.
Further, in a mode shown in FIG. 8, bush shaped sealing members 303 are integrally formed with the flexible wiring board 100.
The sealing member 303 is installed to an insertion hole provided in each of the housings (not shown).
Further, connectors 304 provided at both ends of the flexible wiring board 100 are electrically connected to electric parts within the housings.
Further, as shown in FIG. 1, there has been proposed a mode in combination of FIGS. 7 and 8.
In this mode, the frame body shaped seal 31 is integrally formed on one side of the flexible wiring board 1, and the bush shaped seal 32 is integrally formed on the other side, respectively.
However, the following problem is caused as illustrated in FIG. 6 showing a cross section along a line A-A in FIG. 1.
Generally, the flexible wiring board 1 is provided with the following structure.
A printed wiring layer 12 (a circuit pattern) made of a copper foil is adhered fixedly to one face of a base board 11 made of an elastic material such as a polyimide, a polyamide, a polyester, a liquid crystal polymer or the like.
Next, a cover film 13 made of the same material as the elastic material used in the base board 11 is formed on a front face of the printed wiring layer 12, for protecting the front face.
As a result, the printed wiring layer 12 is structured such as to be sandwiched by the base board 11 and the cover film 13.
Further, the printed wiring layer 12 is generally narrower than a width of the base board 11.
In FIG. 6, the width of the printed wiring layer 12 is one third of the base board 11 or less.
As a result, when a molding pressure is applied at a time of integrally forming the sealing members 3 on the flexible wiring board 1, portions where the printed wiring layer 12 does not exist deform thinly in comparison with a portion where the printed wiring layer 12 exists.
Accordingly, as shown in FIG. 9, gaps 2 and 2 are unavoidably made between a forming metal mold 50 and the flexible wiring board 1, thereby causing a leakage of a rubber material filled at a time of forming, or giving rise to a problem that a burr is made.
As a result, there is caused a problem that the flexible wiring board 1 and the sealing member 3 are not well bonded.
In this case, FIG. 9 shows a cross section in a direction orthogonal to the flexible wiring board 1 of a portion deviating from a region where the sealing member 3 is formed, in a close state of the forming metal mold 50 used at a time of integrally forming the sealing member 3 on the flexible wiring board 1.